Epidemiological study of bacterial and fungal agents of external ear infection in patients Referred to Yasuj Mofatteh Clinic in 2017-8

Otitis media is one of the most commonly reported diseases among patients referring to the ear, nose, and throat clinics around the world. Due to inadequate information on the frequency pattern of the disease-causing species in Kohgiluyeh and Boyer Ahmad province in southwestern Iran, this study was conducted to isolate and identify bacterial and fungal agents of disease in Yasuj city.

During the two-year period, 2017 and 2018, patients with ear infection, referred to ear, throat and nose Shahid Mofatteh Clinic, were sampled. The provided sample was divided into two parts. A part of the sample was used for direct testing and gram staining (bacterial and fungal elements were observed) and the second part was cultured in two sabouraud dextrose agar culture medium  with and without chloramphenicol at  least three points. Phenotypic methods were used to identify the bacterial and fungal agents.

Of the 341 patients studied, 40% were male and 60% were women aged 5 months to 90 years. The prevalence of fungal and microbial infection was 75% (46.5% fungal agents, 23.7% bacterial agents and 4.8% fungal and bacterial infection respectively) and the duration of the disease varied from two days to 29 years. The largest age range involved 31-40 (27%). 69.8% of patients were housewives and 74.6% had history of manipulating the ear canal with contaminated equipment. Major fungal causes of the disease were in the order of frequency, including Aspergillus niger, Aspergillus flavus, and important bacterial agents including Staphylococcus aureus and Pseudomonas aeruginosa. Concurrent infection with fungal and bacterial agents was observed in 16 (4.8%) patients.

Aspergillus niger and Staphylococcus aureus were the most common fungal and bacterial agents that were consistent with the pattern of frequency distribution of factors causing ear infections in Iran. Given that ear manipulation with external devices is one of the most important causes of infection in the present study, providing effective education to citizens can help reduce disease cases. In addition for teaching health tips and treatment, accurate laboratory diagnosis is necessary.